Article View: borland.public.cppbuilder.database.multi-tier
Article #80Re: datasnap access violation
From: Mark Guerrieri
Date: Thu, 31 Mar 2005 22:25
Date: Thu, 31 Mar 2005 22:25
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2283 bytes
> i have used datasnap remote data module to create a multi tier database > application... > i have placed in the remote data module an ado connection ,4 ado tables and > 4 dataset providers..i > have also (of course a form1)..i want to when i click the start/shutdown > button on the Form1 to stop or start the datasnap server...when i try to > stop the adoconnection (with connected->false,or cancel()) i get an access > violation,same for the tables(adotable->active=false) the same for the > dataset providers..it seems that i cant change anything in the remote data > module by using a button on the form1...of course i have included the file > header(<include...)...what am i doing wrong? > the funny thing is that if i put an adoconnection in my form and use a > button to start stop it ,it works perfectly! > By design, the DataSnap server should be running on one machine (with no user interface) and the client that accesses it should be running on another machine. At the least, they would be running in seperate prcesses on the same machine. Either way, there is no way to directly access the properties/methods of the components on the RDM from the client app. Your access violations are most likely the result of accessingg NULL/undefined pointers, since the form in the client has no access to the components in the RDM. Mark
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X-Google-Thread: fcd2b,819ac6fcd9b2eba X-Google-Attributes: gidfcd2b,public X-Google-Language: ENGLISH,ASCII-7-bit From: "Mark Guerrieri" <mguerrieri@nospam_cmsgrp.com> Newsgroups: borland.public.cppbuilder.database.multi-tier References: <423ff302@newsgroups.borland.com> Subject: Re: datasnap access violation Date: Thu, 31 Mar 2005 17:25:34 -0500 Lines: 29 Organization: Creative Marketing Strategies X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 NNTP-Posting-Host: 209.50.174.82 Message-ID: <424c78d6$1@newsgroups.borland.com> X-Trace: newsgroups.borland.com 1112307926 209.50.174.82 (31 Mar 2005 14:25:26 -0800) Path: arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!news4.google.com!newshub.sdsu.edu!logbridge.uoregon.edu!newsfeeds.ihug.co.nz!ihug.co.nz!newsgroups.borland.com!not-for-mail